US4250345A
Expired / Lapsed
US
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Selective production of para-xylene
Assignee: Mobil Oil AS
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Filing: 1978-01-10
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Granted: 1981-02-10
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Expires: 1998-01-10
Abstract
Abstract Process for the selective production of para-xylene by methylation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12, which catalyst has undergone prior modification by the addition thereto of phosphorus oxide and magnesium oxide, each in an amount of at least about 0.25 percent by weight.
Inventors
- 👤 Chin-Chiun Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:34
CPC Classifications
C; C07; C07C; C07C2/00; C07C2/86; C07C2/862; C07C2/865; B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; C07C2/861; C07C2/864; C07C2/868; B01J2229/00; B01J2229/10; B01J2229/26; B01J2229/30; B01J2229/42; C07C2529/00; C07C2529/04; C07C2529/06; C07C2529/40; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
113 words
A process for the selective production of para-xylene which comprises reacting toluene with a methylating agent under methylation conditions in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12, a constraint index within the approximate range of 1 to 12, said catalyst having been modified by the addition thereto of phosphorus oxide and magnesium oxide as a result of incorporation of a compound of phosphorus and a compound of magnesium with said zeolite, each of said oxides being incorporated by impregnation of said zeolite therewith and being present in an amount of at least about 0.25 percent by weight.
Claim 2
Dependent Claim
113 words
A process for the selective production of para-xylene which comprises reacting toluene with a methylating agent under methylation conditions in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12, a constraint index within the approximate range of 1 to 12, said catalyst having been modified by the addition thereto of phosphorus oxide and magnesium oxide as a result of incorporation of a compound of phosphorus and a compound of magnesium with said zeolite, each of said oxides being incorporated by impregnation of said zeolite therewith and being present in an amount of at least about 0.25 percent by weight.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein said crystalline aluminosilicate zeolite is characterized by a silica/alumina ratio in excess of 30.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said methylating agent is methanol, methyl chloride, methyl bromide, dimethylether or dimethylsulfide.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein said crystalline aluminosilicate is ZSM-5.
Claim 6
Dependent Claim
58 words
The process of claim 1 wherein said methylation conditions include a temperature between about 250° C. and about 750° C., a pressure within the approximate range of 1 atmosphere to 1000 psig, a weight hourly space velocity between about 1 and about 2000 and a molar ratio of methylating agent to toluene between about 0.05 to about 5.
Claim 7
Dependent Claim
11 words
The process of claim 4 wherein said methylating agent is methanol.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein phosphorus oxide and magnesium oxide are each present in an amount of between about 0.25 and about 25 weight percent.
Claim 9
Dependent Claim
40 words
The process of claim 1 wherein said phosphorus oxide is present in an amount of between about 0.7 and about 15 weight percent and magnesium oxide is present in an amount of between about 1 and about 15 weight percent.
Claim 10
Dependent Claim
27 words
The process of claim 1 wherein the crystalline aluminosilicate zeolite is combined in an amount between about 1 and about 90 weight percent in a binder therefor.
Claim 11
Dependent Claim
10 words
The process of claim 1 wherein said binder is alumina.
Claim 12
Dependent Claim
16 words
The process of claim 1 wherein the crystalline aluminosilicate zeolite is predominantely in the hydrogen form.
References Cited (Backward Citations)
US3965208A
Cited
US4086287A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |